The present invention relates to a magnetic transfer apparatus for transferring magnetic signals including formatting information or the like from a master disk onto a magnetic disk used in a hard disk drive or a floppy disk, and a method for monitoring particles which can be obstacles to the magnetic transfer of data.
Recent advanced magnetic recording techniques have made magnetic recording devices to have increasingly large capacity and small size. The increase in the recording capacity of hard disk drives due to high density recording is particularly noteworthy. A hard disk drive is normally composed of a plurality of magnetic disks, a plurality of magnetic heads respectively corresponding to each of the magnetic disks, and an electronic circuit for reading recorded signals. The magnetic disks are imprinted with magnetic signals including formatting information and address information during the fabrication process of the hard disk drive. While such writing of magnetic signals onto the magnetic disks can be done using the magnetic heads of the hard disk drive itself, it is the usual practice to transfer magnetic signals from a master disk collectively to several magnetic disks as slave disks, FIG. 4 shows a prior art magnetic transfer apparatus used for transferring data from a master disk to several slave disks.
The magnetic transfer apparatus includes a square casing 10 for accommodating other members. Clean air is supplied into the casing from above so that magnetic transfer is carried out in a clean environment. A cassette 11 accommodating a plurality of slave disks 1 is transferred into the casing 10, and the slave disks 1 are removed from the cassette 11 by a disk handler 13 one by one and transferred to a suction head 3 provided on a rotary index head 4. The rotary index head 4 includes four, equally spaced suction heads 3 along its periphery, so that each of the suction heads 3 moves from one to another of four stop positions A to D as the rotary index head 4 rotates intermittently. A position detector 5, a foreign substance inspection unit 6, a format device 7, and a transfer stage 8 are respectively disposed near or opposite each of the stop positions A to D. Thereby, as the rotary index head 4 rotates, a slave disk 1 held on the suction head 3 successively undergoes position detection, foreign substance inspection, erasion of surface magnetism, and magnetic transfer of data. A master disk 2 is held in the transfer stage 8 at the stop position D, and the slave disk 1 is brought in contact with the master disk 2 when transferring data thereonto.
An extremely high degree of cleanliness within the casing 10 is crucial when carrying out magnetic transfer of signals. Even a slightest amount of dust or particle present in air can constitute obstacles to the magnetic transfer of signals from the master disk 2 to the slave disk 1, which must be in close contact with each other. Particles may also cause scratches on the master disk 2, deteriorating its life. While the interior of the casing 10 is filled with clean air supplied from above, there still remains the possibility that particles are generated from various mechanical members in the casing 10. In prior art, a probe 16 is inserted into the casing 10 through a door 10a for measuring the cleanliness inside the casing. A resin tube 18 connects the probe 16 to a particle counter 17.
With such construction, however, when the door 10a is opened to insert the probe 16 into the casing 10, dust may be generated or outside foreign substances may enter the casing 10, thereby making accurate measurement of cleanliness impossible.
Also, since the source or the cause of the particles are hardly locatable, detection of particles provided no clues for the appropriate measures to be taken.